A nano-sensing system has the characteristics of no requirement on fluorescent or radioactive isotope labelling, high real-time performance, high automation degree, compact structure, convenience in combination with another technology and the like, and has important and broad application prospect in the fields of biosensing, drug development and detection, environment monitoring and the like.
At present, the most common means for implementing a nanosensor is localized surface plasmon resonance, and a sensor based on such an effect has been commercialized. There are mainly two technical approaches for implementing localized surface plasmon resonance: a metal nanoparticle structure and a periodic metal nanostructure. However, the metal nanoparticle structure is weaker in optical response and poor in repeatability, and a disordered nanostructure group may cause interference to optical response. Even worse, a spectral width is usually hundreds of nanometers, so that the metal nanoparticle structure is low in sensitivity and unfavourable for high-accuracy sensing application. An optical signal of the periodic metal nanostructure is obviously enhanced and easily regenerated, while its spectral width is still unsatisfactory, a corresponding sensor is slightly low in sensitivity, and a practical application of a nanosensor is restricted seriously.
Therefore, in order to further improve sensitivity of the nanosensor, it is urgent to further reduce a line width of its spectral response to make the nanosensor applicable to sensing detection under a severer condition of low-concentration micromolecules and the like by adopting a new means.